Persistently base pH

[Pat]

Hi, folks! I've got an "issue" with my new aquarium. I'm very much an "aquarifry" at this point, but I'm reading everything I can get my hands on, and I think I'm getting good info from the LFS.

Environment: 20-gal FW, set up 06/04/02, plastic plants and a substantial piece of bog driftwood for "cover," Bio-Wheel 170 filter, rock bubbler; first fish (5 serpae tetras) introduced 06/07/02.

Ammonia, chlorine, and alkaline levels are great, but I keep getting dark yellow (<5.0) test results for pH with TetraTEST kit. I've been adding a double dose of "pH Up" almost every day, which corrects the pH to neutral, but I know that poor pH stability and sudden change of pH is not good for the fish.

A knowledgeable LFS guy whom I trust picked out a piece of aquarium-safe driftwood, smaller than the one I ended up buying. (He said the only issue was price *then* and I liked the larger piece better.) He later confirmed that the driftwood may be the low-pH culprit.

Should I replace the driftwood with a smaller piece or remove the driftwood altogether? Can anyone recommend a solution that would enable me to keep the driftwood I have but stabilize the pH?

Thanks!
Pat

 

[reefrunner69]

That driftwood will not leach enough tannin to reduce the ph to < 5.0 ph. There is something else going on. First thing you need to do, is to rule out a bad test kit, have someone else test your water. Next test the ph of the water you are using for waterchanges and top off. If it still persists, you may want to go with South American fish, they are used to softer waters with low ph. My money is that it is a bad test kit.

 

[Pat]

Thanks for the answer, Reefrunner.

I tested my (cold) tap water before filling the tank, and again tonight, with the same test kit and in the same manner as I use to test the tank water. Tap water pH is consistently between 8.0 and 8.5 (sky-to-medium blue). I retested my tank water today several hours after adding "pH Up." It came out at a solid 6.0 (greenish-yellow), significantly higher than before treatment with "pH Up" when it tested at <5.0 (very dark yellow).

Would you agree that it's not the test kit in that case? If so, any other explanations?

Thanks!
Pat

 

[reefrunner69]

Thanks for the answer, Reefrunner.
Would you agree that it's not the test kit in that case? If so, any other explanations?

Thanks!
Pat

No it does not rule out the test kit. I am not aware of a test kit that has a range of <5.0 ph to 8.5 ph. Usually you have to buy a high range test kit for 7.0 and up and a low range kit for 7.0 and lower. Please have your water tested by another test kit. Also let your tap water sit out for a couple of days and see if the ph goes down. You said your alkaline levels are great, what is the alkalinity of the tank? Alkalinity is defined as the buffering capacity of water to maintain it's ph.

 

[Pat]

Reefrunner, my test kit doesn't show a pH range below 5.0. It's just that the tank water turns so *dark* yellow that, compared to the color chart, the pH would be <5.0.

I'll do what you suggest for the tap water and, meanwhile, take the test kit to be tested. I'll keep you posted!

Pat

 

[fishfreek]

I doubt its the drift wood aswell but I since it seems like the only thing we have to go in right now is the PH test kit I would suggest maybe getting a bucket and putting some new water that tests at a "normal" ph reading and the drift wood in the bucket. Let it sit for a few days and then test the water to see where the PH has moved.

That would atlesat rule out the driftwood.


I could be totally grasping at straws here since freshwater really is not my area of knowledge.

 

[Pat]

I doubt its the drift wood aswell but I since it seems like the only thing we have to go in right now is the PH test kit I would suggest maybe getting a bucket and putting some new water that tests at a "normal" ph reading and the drift wood in the bucket. Let it sit for a few days and then test the water to see where the PH has moved.

That would atlesat rule out the driftwood.

I could be totally grasping at straws here since freshwater really is not my area of knowledge.

Thanks, Fishfreek. I'll give that experiment a try and report what happens in a couple of days. --Pat